The proposed research would determine histologically the regenerative response of the dental lamina in larval and adult urodele mandibles following excision of dental lamina segments, with or without concomitant dorsal scraping of associated mandibular skeletal elements. Results of 1/4, 1/2 and whole jaw scrapings, involving varying amounts of skeletal elements, should yield some insight as to the dependency of the regenerative response upon a certain quantity of connective tissue elements remaining in the operated stumps to act as a source of cells. Connective tissue from areas associated with, and remote to the mandibles, should be implanted into areas of negative or minimal regenerative response, in order to determine whether the addition of specific or non-specific connective tissue cells is needed to re- establish the expression of a complete regenerative program, including the formation of tooth germs and functional teeth.